new Promise((resolve, reject) => {
  console.log("promise1", 1) 
  resolve()
})
.then(() => {
  console.log("then11", 2)
  new Promise((resolve, reject) => {
      console.log("promise2", 3)
      resolve();
  })
  .then(() => {
      console.log("then21", 4)
      new Promise((resolve, reject) => {
          console.log("promise3", 5)
          resolve();
      })
      .then(() => {
          console.log("then31", 7)
      })
      .then(() => {
          console.log("then32", 9)
      })
  })
  .then(() => {
      console.log("then22", 8)
  })
})
.then(() => {
  console.log("then12", 6)
})  

// promise1 1
// then11 2
// promise2 3
// then21 4
// promise3 5
// then12 6
// then31 7
// then22 8
// then32 9